Episode 1

Series three opens on an odd job: a London black cab sitting abandoned in a wasteland. It looks like a recovery exercise, the sort of call a team answers before breakfast, until it stops looking like one. Whatever is going on with that cab, it is bigger and nastier than the initial report suggests, and Lana and her team are in it before they know what they have walked into.

The bombings follow quickly, and at first they read as large-scale terror work, the kind that gets the whole machine moving. Then the pattern sharpens. The targets are personal, picked for who they are, and the vendetta underneath the violence starts to show itself. Chris Brandon and Daniel Brierley's script spreads the puzzle across London and makes the team do the unglamorous work of joining the dots between events that should not connect, while the loose ends grow with every scene and nobody looks like they are keeping up comfortably.

Jamie Donoughue directs, keeping the mood grim without tipping into gloom; the violence lands hard but never feels like a special effect. Vicky McClure anchors the hour as Lana, and she has good support in Lucy Allen's Agnes Raffner, Katie Bernstein's Jenny Manning, Nabil Elouahabi's Hassan Rahim and Jason Flemyng's Steven Wyles. Kerry Godliman's Sonya Reeves, Michael Gould's Ned Cole, Christopher Hatherall's Phil Croxley, Mark Rowley's Rich Manning and Eric Shango's Danny round out the cast.

It is a slow-burning opener, more interested in motive than mayhem, and all the better for it. The episode feels contained, almost local, while the implications keep stretching further out into the season. A lonely cab in a wasteland turns out to be the right image to start on: something out of place, waiting to be understood. And it does the one thing a season premiere must, it makes you want the next one.